178 MUTATION 



discontinuous groups with respect to the colora- 

 tion of the under side of the wings, a, " leaf- 

 veinings " absent or nearly so, ground nearly 

 plain; h, ground without veins but with promi- 

 nent black speckled spots; c, veins strong, no 

 blotches ; d, with blotches, with or without veins. 

 Here at least three unit characters appear; dark ^ 

 lines (veins), black speckled spots, and blotches; 

 but one or all may be absent from a given wing. I 

 Between presence and absence of the character 

 no intergrades occur except possibly in the case 

 of " nearly absent " veins. There is reason for 

 concluding that even in Kallima new characters 

 arise fully formed, and that these are numerous 

 enough to afPect all the detail of the pattern. If 

 the combination of pattern characters is pro- 

 tective, no doubt it will preserve many individ- 

 uals from elimination. 



There is, moreover, still another way in which 

 mutations may become adaptive; and that is by 

 their possessor selecting a habitat that fits its 

 organization. At the risk of encroaching on the 

 subject of adaptation, assigned to another, I may 

 give an illustration. The whole surface of the 

 earth is scattered over with spores and seeds of 

 plants and the resistant eggs and gemmules of 

 various lower animals. Only if conditions are 

 propitious will they hatch or germinate. Some 

 years ago a dam broke at Cold Spring Harbor 

 in February and drained a lake of eighty years' 

 standing. In the Spring a luxurious terrestial 



